Apparatus for the distribution of gases under pressure by means of liquefied gases



l t e v e h4 s j 2 PICARD Filed DeC. 18, 1928'.

PRESSURE BY MEANS OF LIQUEFIED GASES Jan. 24, 1933.-

' APrARATus PoR THE DISTRIBUTION oF GAsEs UNDER half/95 Pian/'d 4 wem Jan. 24, 1933. C, PlCARD APPARATUS FOR THE DISTRIBUTION 0F GASES UNDER PRESSURE BY MEANS 0F LIQUEFIED GASES 2 Shets-Sheet. 2

Cdgj Inventor Filed Dec. Y1s, 1928 Attorneys Patented Ju. 24, 1933 UNITED STATES PATENTl OFFICE i CHARLES PICAB'ID,l OF J'OINVILLE LE PONT, FRANCE, ASSIGNOR T0 UAB LIQUIDE SOCIT ANONm POUR LETUDE & LEXVPIDITATION CLAUDE, OF PARIS, FRANCE APPARATUS POB THE DISTRIBUTION F DES PBOCEDES GEORGES @sans UNDER rnrssvmi BY' or* LIQUEFIED GASES Application illed December V18, 1928, Serial No. 326,895, and in France December 20, 19W.

This invention relates to methods and apparatus for distribution of gases under pressure by means ofV liquefied gases, for example for distributing gaseous oxygen under pres-v sure by means of vliquid oxygen. I

The arrangements heretofore proposed for such a distribution of oxygen necessitate an apparatgs-ffrom which certain dan ers may arise on account of the pressure eveloped therein by the vaporization of the liquid oxygen itself and further on account of the impossibility of preventing the entrance of heat from the exterior so that a spontaneous vaporization cannot be prevented when gaseous oxygen is not Withdrawn with the resulting possibility of an increase of the pressure beyond permissible limits.

The present invention has for its object to obviate the disadvantages-above referred to. For this purpose according to the invention the liquefied gas is introduced into containers under no or almost no pressure and is converted, near the place where it is to be used, into gas under pressure by means of a liquid pu-mp and a vaporizer.

Preferably the pump is located in the container and discharges into the vaporizer; consequently, as the pressure is created by the pump, thisl pressure, and the parts of the apparatus to which itis applied, can be controlled; when the pump is not working, these latter may be limited to a simple receptacle of the usual character filled with gas at a pressure of about 150 kilograms per square centimetre.`

Another feature of the present invention consists in the special constructionof theforce pump for the liquelied gas as will be described hereinafter.

In order that the said -invention maybe clearly understood and'readily carried into effect the same will be more fully described with reference to the accompanying drawings which illustrate diagrammatically and by way Y of example an apparatus for carryinout the present method, and in which igure 1 1s a view of the plant as a whole, Figure 2 a detail view of the pump, and Figure 3 a section on the line A- B of 2' Figure,

'R is a container for the liquefied gas in which it is transported or whlc'h is permanently located at the place where it is to be used. Into this container there is introduced through the part open to the air a pump carried on the frame B and consisting of two main parts: the compression cylinder and the mechanism controlling the piston; thesetwo parts are connected together by tubes or rods preferably of metal of poor heat conductivity and of dimensions as small as possible in order to reduce the calorific capacity thereof. Only the compression cylinder C dips into the liquefied gas, the control mechanism being completelyoutside the receptacle R. This cylinder C is connected to the pump control mechanism by means of a thin tube T preferably made of a metal of poor heat conductivity. In `the cylinder C reciprocates a plunger piston P, preferably provided with grooves, and connected to the sliding guide head X `by a thin rod or a tube E, which is also preferably made of'a metal which is a poor conductor of heat. The piston P may be metallic or"constructed of plastic materials, such as a series of discs of dressedleather, etc.

, The cylinder C is provided with lports LI It has furthermore been-found necessary,

in order to ensure va good output from the v pump, to cool the body of the same, as heat might be disengaged by friction and by the compression of the liquid, thereby causing the formation of gas in sufficient quantityto interfere with the Working. For this purpose the cylinder C is provided with gills .U of sufficient surface to dissipate the heat developed in the body of the pump and thus prevent vaporization of the liquid in the interior of the cylinder C.

The pump 1s provided Iat its lower I art with a discharge valve the seat -ofrwhich 1s prefer- 100 abl made of slightly plastic material, such as bre which has been recognized as providing a tight joint, or of pure copper; the valve may be constituted by a simple ball. t

It is also necessary to avoid the introduction of any solid particles into the pump, as in consequence of the very low temperatures and the absence of lubrication, theseparticles would at once cause a seizure. For this purpose the inlet ports are covered with very linev metallic gauze C capable of stopping the particles of ice and solid carbon dioxide generally ound in liquid oxygen.

A sleeve M of smaller diameter than the guide I-I and a flat part N prevent the lubricating oil from the slide falling into the cylinder C and into the container R. v

The liquid from the container R', drawn in by the piston I), enters the cylinder C through the ports L, and is forced through the valve D into 'a pipe F made of metal of poor heat conductivitywhich leads into a vaporizer G, where the liquid is converted into gas, this vaporizer G being maintained at the required temperatureby any desired method of heating. The gas thus produced passes under pressure to the place where it is to be used or stored. Y

A convenient method of effecting this heating, when the pumpis worked electrically, consists in passing the current through a heating resistance situated in the vaporizer and which only acts when the pump is working, being automatically cut out of the circuit on the stoppage of the pump.

According to this method the electric current is supplied to the motor l actuating thepump from the source of power 2-3 through a switch 4; the heating resistance 5, situated 1n the' Wall of the vaporizer G, is shunted on the circuit of the pump at 6 7, after the' switch 4, so 'that this switch, when turned on, supplies the current simultaneously to the motor 1 and tothe heating resistance.

When the desired pressure in the distributor pipe 8 of compressed gas has been reached.

" this pressure actuates automatically a switch 9 which cuts oil the current supplyto the pump and to the heating resistance.

yThe pressure of the gas may be as high as desired; if it is necessary to maintain a pressure approximately constant in the supply pipes, there may be attached to the pump an automatic starter which starts the pump working when the pressure in the pipes tends to drop and which stops it when the pressure is sufficiently high.

Ic1aim:. A' 'l 1. In a pump for liquefied gases at low boiling-point, a cylinder dipping in the liqueliedt gases and means for dissi-pating the heat developed in the cylinder by the movement of the piston in its cylinder.

2. In a pump for liquefied gases at low boiling point,`a cylinder dipping in the liqueof the pump.

lied gases, means for dissipating the heat developed in the cylinder 'by the movement of the piston in, its cylinder and a discharge valve the seat of which .is made of slightly plastic material.

3. In a pump for liquefied gases at low boiling point, a cylinder dipping in the liqueied gases, means for dissipating the heat developed in the cylinder bythe movement of the piston inv its cylinder and a discharge valve the seat thereof beingmade of copper.

4.-. In a pump for liquefiedv gases a cylinder dipping in the liquid, a tube surrounding the actuating rod of thepump and spaced from this rod, and means 'for preventing the lubricating oil at the sliding guide head to penetrate in the cylinder.

5. In a pump forliqueied gases, electrically driven by a motor and forcing the liqueed gases into a vaporizer heating means for electrically heating the vaporizer by the electric current which supplies the said motor and means for cutting automatically the said heating means out of the circuit on the stoppage 6. In a pump Jfor liquefied gases at low boilingpoint, a cylinder dipping in the liqueied y gases, provided with suction and discharge valves, means for dissipatingthe heat developed in the cylinder by the movement of the piston in its cylinder and ports situated in the wall oi? the cylinder, vthe upper edges of them being substantially flush with the under face of the piston at the end of its suction stroke.

gases, provided only with discharge" valve,

means for dissipating the heat developcdin the cylinder by the movement of the piston in its cylinder and ports situated in the wall of the cylinder, the upper edges of them being IDO substantially Hush withA the under face of the piston at the end of its suction stroke. 8. In a pump for liquefied gases a cylinder dipping in the liquid, a tube sustaining the said cylinder and an actuatin rod for the piston surrounded by the said tu e and spaced' therefrom. Y

In witness whereof I have hereunto set my hand.

' CHARLES PICARD. 

